1). Field of the Invention
This invention relates to an electronic assembly of the kind having a plurality of integrated circuit dies stacked onto one another, and its manufacture.
2). Discussion of Related Art
In conventional computer assemblies, integrated circuits are “two-dimensionally” connected to one another. Two dies may, for example, be mounted to a common substrate having metal lines that interconnect the integrated circuits of the dies with one another. A “three-dimensional” interconnection scheme may in certain instances be more desirable. Handheld devices may, for example, require a more compact packaging arrangement. In other applications, the metal lines in substrates may inhibit performance. Other applications may also require a three-dimensional interconnection scheme to allow for the design of more sophisticated, three-dimensional logic.
Some techniques for forming contacts on a substrate side of a die are disclosed in U.S. Pat. No. 6,184,060. These techniques are in some respects undesirable, because they require etching of an opening in a die. Etching is relatively slow. Etching also requires many photolithographic steps. All of these factors contribute to limiting throughput.